Field of Invention
The present invention relates to a composition for film formation, a film, a production method of a patterned substrate, and a compound.
Description of the Related Art
In manufacturing semiconductor devices, multilayer resist processes have been employed for attaining a high degree of integration. In these processes, a composition for resist underlayer film formation is first coated on a substrate to provide a resist underlayer film, and then a resist composition is coated on the resist underlayer film to provide a resist film. Thereafter, the resist film is exposed through a mask pattern or the like, and developed with an appropriate developer solution to form a resist pattern. Subsequently, the resist underlayer film is dry-etched using the resist pattern as a mask, and further the substrate is dry-etched using the resulting resist underlayer film pattern as a mask, thereby enabling a desired pattern to be formed on the substrate. Resist underlayer films used in such multilayer resist processes are required to have optical characteristics such as the refractive index and the extinction coefficient, as well as general characteristics such as etching resistance.
The multilayer resist processes involving a procedure of forming a hard mask as an intermediate layer on the resist underlayer film has been studied recently. Specifically, since an inorganic hard mask is formed on a resist underlayer film using a CVD technique according to this procedure, particularly in a case where a nitride inorganic hard mask is formed, the temperature is elevated to be as high as at least 300° C., and typically no less than 400° C., and thus, the resist underlayer film is required to have superior heat resistance. When the resist underlayer film has insufficient heat resistance, a component in the resist underlayer film may be sublimated and the sublimated component may adhere to the substrate again, resulting in a disadvantage of a decrease in yields of the production of semiconductor devices.
Still further, patterns are more frequently formed recently on a substrate having a plurality of types of trenches, in particular trenches having aspect ratios that differ from each other, and the resist underlayer film formed is desired to sufficiently fill these trenches and also have superior flatness.
To meet these demands, structures of polymers, etc., to be contained in a composition, and functional groups included in the polymers have been extensively investigated (see Japanese Unexamined Patent Application, Publication No. 2004-177668). However, it has been still impossible to sufficiently meet the demands described above, according to the conventional compositions described above.